The plans for the Plastruder MK6 look downright wicked
MakerBot just released the photostream and wiki instructions for the Plastruder MK5. This looks like a total overhaul of their original designs.
It is based on Charles Pax’s Paxtruder which has such a small form factor that it is possible to squeeze two extruder heads into one Makerbot. The Paxtruder also uses a delrin plunger which is used to push the filament against the extruder pulley, rather than the previous idler wheel design. I like the delrin plunger idea since it would be a lot easier to adjust tension and remove/insert filament. The idler wheel held in by a large bolt and nut works… but is finicky and sometimes prone to fussiness.
Out are the big/small/weird and whimsical dinos in favor of lasercut acrylic “arches.” There may be a benefit to the arches over the dinos, but I’m not sure what it would be.
The entire heater element and extruder head has been redesigned as well. I don’t recall seeing any published designs which reference this new system. We’ve all seen power resistors in use in RepRap/MakerBot projects – but they’ve usually been relegated to heated build platform designs. Now a pair are being used as the full heating element in place of tempermental nichrome wire. The problem with the old nichrome wire wrapped around the barrel system is that if you need to rebuild the heater, you’ve got to toss out the old nichrome since the insulation is going to get peeled off as soon as you pull it off the barrel.
The new MK5 system uses a PTFE sleeve to feed the filament down into the heater. Interestingly, the PTFE sleeve is encased in a snug metal tube which should prevent any bulging problems.
My understanding of the instructions is that the MK5 is far less prone to failure than the previous MK4 model Plastruder. I’ll grant the Plastruder is easily the most challenging component of the Makerbot to get working.
The instructions also hint at Generation 4 electronics. Right now I’m rockin’ the Gen 3 which have served me quite well. I wonder what the Gen 4 has in store? One thing I have to really like about the electronics is that I know they’ll never really be obsolete. If I wanted to upgrade to Gen 4, I can always print off a Mini-Mendel or Mendel, and swap in the new electronics.
However, if this new system is as resilient as the instructions describe, I’m on board. I’m probably not going to have a good excuse to test out this new Plastruder design for a while since my Plastruder has been behaving itself since the last time I rebuilt my Plastruder and I just scored some spare MK4 parts.
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Ultimaker
Erik de Bruijn along with a newly formed Dutch RepRap group have put together this new design for a low cost RepRap alternative. The stated goal of their blog is “designing/developing an easy to build low cost 3D printer with a small form factor but large build envelope.” Erik has invited everyone to comment on this beta design. It’s interesting to see their progression of prototypes in their second blog post.
The interesting thing about this model is that it combines some of the best parts of Darwin and MakerBot and what appears to be a Bowden extruder.
The very nature of FDM means that the robot will only move the Z axis a little bit every once in a while. One of the design drawbacks to the Darwin was that the heavy extruder head (motors, gears, heating elements) were so heavy that the entire robot would rock or vibrate with the lateral XY movements. MakerBot got around the heavy extruder head problem by moving the platform in the XY and moving the extruder head only up and down. This design decision isn’t without it’s tradeoffs, however. One downside is that their build area is much smaller than a Darwin. Another downside of the MakeBot design is that once the object being built reaches a sufficiently large volume or height, moving the object around quickly on the XY platform causes it to vibrate, shake, and become somewhat unstable.
One of the main improvements inherent in the Bowden extruder is that it allows you to take the heaviest parts of the extruder head, separate them from the rest of the extruder head, and move those heavy pieces to a different location. Using a Bowden extruder makes a Darwin style robot much more feasible – the small moveable print head won’t have the mass to cause the robot to become unstable.
It seems that combining either of the X or Y movements with the Z probably won’t matter all that much, since the Z axis will only move about 0.33mm or so per layer and the Z axis typically doesn’t operate at the same time as either the X or Y axis. Combining the as the new RepRap version II, Mendel, design shows us that combining the Z axis along with either the X or Y axis, but not both, can lead to a very stable configuration.
What I like about the Ultimaker design is that it would appear to incorporate some of the best parts of the MakerBot and Darwin designs. It appears to have a bolt/nut/T-slot MakerBot style assembly structure using thin lasercut wood pieces for the body. I found these parts to bolt together very quickly. Contrast this to the Darwin/Mendel structure using lots of nuts and threaded rod and printed plastic parts to hold it together. At the same time, by making use of a Bowden extruder and the Darwin body shape, it appears to be able to use most of the interior volume for printing.
I suspect it probably uses fewer parts than a typical Darwin, but I can’t be sure. I also have to wonder about the cost of lasercut wood versus the cost of nuts and threaded rod.
Nice find RepRap Log Phase!
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I saw this video the other day (I think as a result of someone’s Tweet?) and just around to watching it now. The things people built using data that had been opened up from the government was pretty incredible.
Interestingly, I have a totally different website that operates by only using data that is already freely available from the government. If I had more data from the government, my site would be even more useful to my demographic.
All of this, the video, my own website, got me thinking – if the data from the government can be released as “open data” – in what ways is our government already open source? We know the laws that supposedly govern us and our administrators… I suppose, open source is the ideal upon which our government was founded in the first place.
Video from Streetfilms covered by PlanetGreen/Discovery.com Tweeted by PlanetGreen RT’d by clothbot.
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